The invention relates to a container for liquid and/or solid substances, having a container body which is of double-walled form in the base and circumferential regions as a result of an inner container inserted into an outer container and continuously cylindrical from the base to the filling aperture, and has at its top a filling aperture which is of circular outline in plan view and can be hermetically sealed by a pivotable lid with an annular seal, which lid, at least in a part-region on the container side in the closed state, is of circular form such that it can be pivoted to fit into the inner container and is provided with locking means which are optionally actuable from a position retracted from locking seatings provided on the container body into a position engaging with positive fitting into the locking seatings, the annular seal being disposed in the part-region of the lid lying within the filling aperture in the closed position of the lid and being formed as a continuous sealing ring of elastomeric material, whose external diameter in the underformed state is substantially equal to or only slightly smaller than the clear internal diameter of the inner container and whose internal diameter is substantially equal to or only slightly larger than the external diameter of the lid in the region retaining the sealing ring in its intended assembly position on the lid.
Containers which can be used, for example, for the transportation of wastes or of environmentally hazardous substances such as chemicals, oils and similar liquids, and which therefore have to be sealingly closeable and resistant to the action of external forces, are known (e.g. DE 41 10 847 C2, DE 43 21 199 C2), the actual container body in such cases still being retained in a framework formed by sections enclosing it, which framework has fork guides in the base region for receiving a fork of a fork lift and respective stacking corners in the upper region which permit a plurality of containers to be stacked one upon the other. The known containers have proved highly suitable for specific uses. Because of the fact that they have a filling aperture of significantly reduced diameter by comparison with the internal diameter of the container body, however, their emptyingxe2x80x94for example, when filled with a flowing content or pieces of solid contentxe2x80x94is critical, especially if the contents tend to adhere or harden. Cleaning of the emptied container through the narrowed aperture is also laborious and also difficult to verify, especially in the region of the container lid surface in the regions adjoining the filling aperture.
U.S. Pat. No. -A-5 083 509 has disclosed a container which comprises a continuous cylindrical inner container without a tapered mouth, but which is intended not as a transportation and storage container but exclusively as a refuse container for solids, and comprises compacting means by means of which the refuse introduced can be compressed into packet form. For this purpose, the container is provided with a compression piston displaceably disposed in the inner container and performing a compression stroke towards the sealed container mouth through evacuation of the space containing the refuse to be compressed. After opening of the container seal, the compressed refuse packet can then be removed from the container. The auxiliary units necessary to evacuate the container, such as the motor-driven suction pump, valves, etc., are in this case disposed below the base of the inner container within an installation space formed by the lengthened outer container.
By contrast, it is an object of the invention to provide a container suitable as a collection, transportation and storage container for all contents in the form of all liquid, pasty and flowing contents, or solid contents in piece form, which is so designed that it is fundamentally authorizable and suitable for all hazardous categories, in other words also including hazardous goods.
Starting from a container of the type referred to initially, this object is achieved, according to the invention, in that the lid, in its end region facing the interior of the container, comprises a peripheral, radially projecting flange which is adjoined, in the direction away from the interior of the container, by a cylindrical peripheral wall on which first the sealing ring and then a continuous cylindrical tensioning ring are disposed to be displaceable in the longitudinal direction of the container, and in that the tensioning ring projects beyond the end wall of the lid on the interior of the container, in the direction away from their interior of the container, and adjustment means for the optional displacement of the tensioning ring in the direction leading towards the interior of the container or out of the interior of the container engage onto the region of the tensioning ring projecting beyond the lid end wall. As a result of the configuration of the container at the filling end, such that the container body virtually no longer has a separate filling aperture but is open at the top and the lid, which in the closed position engages to fit partially into the open container, thus ensures free access to the interior of the container in the opened position, not only the complete emptying of the container and verification thereof but also any careful cleaning thereof that may be necessary are readily possible. In particular, automatic cleaning devices can also be developed, with which, in addition to cleaning with high-pressure jets of cleaning fluid, revolving brushes can be employed whose use is not obstructed or made more difficult by a narrowed filling aperture. By actuating the adjustment means in such a way that the tensioning ring is displaced towards the interior of the container, it is brought into contact with the sealing ring and then deforms it elastically in such a way that it rests both on the inner surface of the inner container and on the cylindrical peripheral wall of the lid, with prestress. The increase in pressure occurring in the interior of the container, which may be attributable, for example, to gaseous constituents released by the contents on warming, additionally deform the sealing ring and so increase the force of its contact pressure on the inner wall of the container or the cylindrical peripheral wall of the lid.
In an advantageous further development of the invention, the outer container may have a shape which is polygonal, preferably octagonal, in plan view, and in that the cylindrical inner container is disposed in concentric orientation to the outer container and its external diameter is at least slightly smaller than the clear distance measured between the interior surfaces of the outer container. The container body is thus of double-walled configuration, the polygonal shape of the outer container being strengthened, by comparison with a cylindrical outer container, by the bending edges formed, in the manner of beading, between the respective part-surfaces of the polygon.
In an advantageous further development of the invention, the outer container comprises a substantially square base plate, whose diametrically opposite limiting edges are oriented substantially flush with the outside of the assigned opposite part-surfaces of the outer container.
In the corner regions of the base plate projecting beyond the outer surfaces of the outer container a metallic corner section extending to beyond the filling aperture in the vertical direction is in each case expediently provided, which corner sections are part of a framework enclosing the container body.
The adjustment means for displacing the tensioning ring are expediently configured from locking elements distributed in the peripheral direction on the top, remote from the container, of the lid end wall beyond the periphery thereof, and guided in a substantially radially displaceable manner and capable of being advanced into and retracted from respectively assigned apertures in the tensioning ring, which locking elements each engage into the respectively assigned aperture in the tensioning ring by a limiting surface which in each case tapers from inside to outside. The adjustment of the tensioning ring is thus effected by the tapering limiting surfaces which act in the manner of wedges.
The locking elements may then advantageously be extended radially outwards via the tapering limiting surface engaging into the respective aperture in the tensioning ring, up-ward-projecting tabs with apertures as locking seatings for the locking element extensions being provided substantially flush with the apertures in the tensioning ring of the container body. In addition to the non-positive retention of the lid in the interior of the container via the deformed annular seal in the closed position, therefore, a mechanical locking is achieved here by the lock extensions which, with a suitable configuration, remains effective even if the sealing ring is partially or completely detensioned by retraction of the locking elements. This provides security against sudden opening of the lid as a result of super atmospheric pressure that has arisen in the interior of the container.
In an advantageous further development a head, enlarged in diameter by comparison with the locking extension, is provided in each case on the free outer ends of the locking extensions, the diameter of which head is in each case smaller than the diameter of the assigned aperture, provided as a locking seating, in the upward-projecting tabs.
Expediently, the head provided at the free end of each locking element extension comprises a limiting surface tapering radially and frustoconically outwards, which guides the head, during the locking operation, into the assigned aperture provided as the locking seating.
The locking elements, for their part, may be each connected via an elongate shank section to an assigned lever arm rotatable about the central axis of the container, the lever arms for the actuation of the locking elements expediently being disposed on a common actuating element rotatable about the central axis of the container, on whose upper end, projecting from the lid, a manually actuable lever-like handle is provided. Instead of individual lever arms projecting radially in each case from the rotatable actuating element, these lever arms may also form part of a common actuating plate projecting radially over the actuating element, in the peripheral region of which the actuating rods are each articulated offset relative to one another in the peripheral direction.
Because of the specific outer shape of the container, a configuration is recommended in which a total of four locking elements, each offset relative to one another by approximately 90xc2x0 in the peripheral direction, are provided on the top of the lid end wall and the tabs provided with apertures serving as locking seatings are each disposed to project in the vertical direction from the upper edge of the container body above the projecting corner regions of the base plate.
The dimensions and the position of the outward-tapering limiting surfaces provided on the locking elements and engaging into assigned apertures in the tensioning ring and the locking element extensions, and also the effective length of the lever arms rotatable about the central axis of the container, are, in an advantageous further development of the invention, so matched to one another that, in the event of a rotational actuation of the handle out of the closed position of the lid over a first partial actuation path, the tensioning ring is released in the vertical direction to such an extent that the sealing ring, which in the closed position of the lid is deformed by the tensioning ring into sealing contact on the inner container, is deformed back elastically into its initial shape, the locking element extensions still engaging through the apertures, serving as locking seatings, in the tabs and are only retracted out of the apertures in the tabs on further rotational actuation over the residual actuation path. It is thereby ensured that the sealing ring is already completely detensioned and consequently a reduction in pressure in the interior of the container is possible, while the lid is still mechanically secured against opening by the locking element extension.
With a configuration of this type, it is advantageous if a stop device which is active between the lever-like handle and the lid and can be manually inactivated is provided, and, on actuation of the lever-like handle out of the closed position, becomes active after one rotation over the first partial actuation path. This excludes the possibility that the lever-like handle may be opened so quickly, in one movement, that the detensioning of the sealing ring and the mechanical unlocking of the lid by means of the locking element extension take place virtually simultaneously and the lid may thus spring open as a result of the internal pressure that has arisen within the container and endanger the operator. In this case, the stop device advantageously comprising a stop assigned to the lever-like handle and projecting towards the top of the lid, on the one hand, and a counter-stop projecting upwards from the lid and disposed in the actuation path of the stop on the other hand, the stop assigned to the lever-like handle being configured to be manually moveable out of its stop position in which it comes to rest against the counter-stop.
In this case, expediently, the stop is resiliently pretensioned in the stop position against the counter-stop and can be adjusted out of the stop position by an unlocking element assigned to the lever-like handle, without encompassing, against the spring prestress.
The lid is preferably pivotably articulated on the upper edge of the container body and, in a further development according to the invention, can be pivoted through more than 90xc2x0.
An expedient embodiment here is one in which the lid can be fixed, by a manually actuatable lid securing device, in an intermediate position in the range between approximately 90xc2x0 and 120xc2x0.
In a preferred embodiment of the invention, the lid is articulated on the container body via a joint mechanism which guides the lid, during the start of the opening movement, initially with a movement component oriented substantially out from the inner container and only makes the transition to the pivot movement after the lid has emerged from the mouth of the inner container. Joint mechanisms with these kinematics are known, for example, from the joint hinges employed today in furniture construction. Thus, for example, a basically suitable joint mechanism here is what is known as a four-joint mechanism, the kinematics of which are expediently such that the lid, pivoted into and fixed in the intermediate position, is laterally offset relative to the container body in plan view and the interior of the container is thus accessible for the introduction of a filling or extraction member or, alternatively, the introduction of cleaning equipment from the top.
As the lid of the container according to the invention may be comparatively heavy because of its relatively large diameter, by comparison with known containers, and the complex tensioning and locking mechanism, it is advisable for a spring prestress device to engage on the joint mechanism and, at least during the first part of the opening movement of the lid out of its closed position, generates a force oriented in the opening direction which at least partially compensates for the weight of the lid acting in the closing direction.
The container according to the invention is produced, expediently to a large extent but at least in respect of its parts coming into contact with the container contents, from a corrosion-resistant metal alloy which is also chemically resistant to the contents.